Reconstitution of Hepatic Microsomal Stearoyl-Coenzyme A Desaturase System from Solubilized Components*

Shimakata, Takashi; Mihara, Katsuyoshi; Sato, Ryo

doi:10.1093/oxfordjournals.jbchem.a130004

Cited by 170 publications

(39 citation statements)

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“…) after NADPH addition to the microsomal fraction (Shimakata et al 1972). 7-ethoxyresorufin O-deethylase (EROD) and 7-penthoxyresorufin O-deethylase (PROD) activities were determined at 30°C using 10 and 60 min incubation times, respectively, essentially as described in Burke & Mayer (1974) and Lubet et al (1985); 10 µl of microsomes (EROD) or 100 µl (PROD determination) were incubated in a final volume of 1.0 ml containing 90 mM KH 2 PO 4 /K 2 HPO 4 , pH 7.4, 0.22 mM NADPH and 3.8 µM 7-ethoxyresorufin or 7-penthoxyresorufin.…”

Section: Methodsmentioning

confidence: 99%

Assessment of coastal pollution by combined determination of chemical and biochemical markers in Mullus barbatus

Porte¹,

Escartı́n²,

Parra³

et al. 2002

Mar. Ecol. Prog. Ser.

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Muscle concentrations of organochlorinated compounds as well as biliary levels of polycyclic aromatic hydrocarbon (PAH) metabolites were determined in red mullet Mullus barbatus as a sentinel species for assessing the pollution along the western Mediterranean coast. A battery of biochemical markers -biotransformation and antioxidant enzymes -were also measured in liver subcellular fractions to assess exposure to pollutants. Among them, 7-ethoxyresorufin O-deethylase (EROD) activity, as well as 7-penthoxyresorufin O-deethylase (PROD) activity and cytochrome P450 1A (CYP1A) content evidenced strong differences among sampling sites, and a good correlation with the amount of PCBs bioaccumulated by fish. No clear pollution-related response was observed for cytosolic glutathione S-transferase, whereas uridine-diphosphate UDP-glucuronyltransferase (UDPGT) was elevated in fish from polluted sites. Antioxidant enzymes -superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) -were used to assess oxidative stress. Among them, catalase activity was well related to PCB body burden.

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Section: Methodsmentioning

confidence: 99%

Assessment of coastal pollution by combined determination of chemical and biochemical markers in Mullus barbatus

Porte¹,

Escartı́n²,

Parra³

et al. 2002

Mar. Ecol. Prog. Ser.

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“…Scd plays its central role in partitioning endogenous and dietary fatty acids into metabolically active or inactive pools and is a key enzyme of mono-unsaturated fatty acid (MUFA) biosynthesis. Scd1 requires the presence of NADH-reductase, cytochrome b5 and oxygen to catalyse the introduction of a cis double bound at delta-9 position of palmitoyl-or stearoyl-CoA to form palmitoleyl-or oleyl-CoA, respectively (Shimakata et al 1972). Thus, most oleic acid is synthesized from endogenous delta-9 desaturation of C18:0.…”

Section: Introductionmentioning

confidence: 99%

Distinct regulation of stearoyl-CoA desaturase 1 gene expression by cis and trans C18:1 fatty acids in human aortic smooth muscle cells

et al. 2011

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Consumption of trans fatty acids is positively correlated with cardiovascular diseases and with atherogenic risk factors. Trans fatty acids might play their atherogenic effects through lipid metabolism alteration of vascular cells. Accumulation of lipids in vascular smooth muscle cells is a feature of atherosclerosis and a consequence of lipid metabolism alteration. Stearoyl-CoA desaturase 1 (scd1) catalyses the production of monounsaturated fatty acids (e.g. oleic acid) and its expression is associated with lipogenesis induction and with atherosclerosis development. We were interested in analysing the regulation of delta-9 desaturation rate and scd1 expression in human aortic smooth muscle cells (HASMC) exposed to cis and trans C18:1 fatty acid isomers (cis-9 oleic acid, trans-11 vaccenic acid or trans-9 elaidic acid) for 48 h at 100 lM. Treatment of HASMC with these C18:1 fatty acid isomers led to differential effects on delta-9 desaturation; oleic acid repressed the desaturation rate more potently than trans-11 vaccenic acid, whereas trans-9 elaidic acid increased the delta-9 desaturation rate. We then correlated the delta-9 desaturation rate with the expression of scd1 protein and mRNA. We showed that C18:1 fatty acids controlled the expression of scd1 at the transcriptional level in HASMC, leading to an increase in scd1 mRNA content by trans-9 elaidic acid treatment, whereas a decrease in scd1 mRNA content was observed with cis-9 oleic acid and trans-11 vaccenic acid treatments. Altogether, this work highlights a differential capability of C18:1 fatty acid isomers to control scd1 gene expression, which presumes of different consequent effects on cell functions.

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“…These UFAs play an essential role in homeoviscous adaptation (11) and are synthesized in fungal and animal cells by acyl coenzyme A (CoA) ⌬ 9 Z-desaturases (3,5,30,31), which have significant levels of conservation of amino acid sequence and inferred transmembrane structure (20,31). Functional replacement of OLE1 with a cDNA encoding a rat desaturase indicates conservation of the functional interactions between desaturases and two essential electron transport components of the active desaturase complex, cytochrome b 5 (a hemoprotein) and cytochrome b 5 reductase (flavoprotein) (12,22,24,27,28). Recently, cDNAs encoding integral membrane desaturases of lepidopteran insects (moths) have also been shown to relieve the UFA auxotrophy of ole1 mutants of S. cerevisiae and to produce unique UFA profiles that reflect the distinctive substrate selectivities and regioselectivities of the expressed desaturases (17,18,20,25).…”

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confidence: 99%

Ethanol Tolerance in the YeastSaccharomyces cerevisiaeIs Dependent on Cellular Oleic Acid Content

You

Rosenfield

Knipple

2003

Appl Environ Microbiol

286

200

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In this investigation, we examined the effects of different unsaturated fatty acid compositions of Saccharomyces cerevisiae on the growth-inhibiting effects of ethanol. The unsaturated fatty acid (UFA) composition of S. cerevisiae is relatively simple, consisting almost exclusively of the mono-UFAs palmitoleic acid (⌬ 9 Z-C 16:1 ) and oleic acid (⌬ 9 Z-C 18:1 ), with the former predominating. Both UFAs are formed in S. cerevisiae by the oxygen-and NADH-dependent desaturation of palmitic acid (C 16:0 ) and stearic acid (C 18:0 ), respectively, catalyzed by a single integral membrane desaturase encoded by the OLE1 gene. We systematically altered the UFA composition of yeast cells in a uniform genetic background (i) by genetic complementation of a desaturase-deficient ole1 knockout strain with cDNA expression constructs encoding insect desaturases with distinct regioselectivities (i.e., ⌬ 9 and ⌬ 11 ) and substrate chain-length preferences (i.e., C 16:0 and C 18:0 ); and, (ii) by supplementation of the same strain with synthetic mono-UFAs. Both experimental approaches demonstrated that oleic acid is the most efficacious UFA in overcoming the toxic effects of ethanol in growing yeast cells. Furthermore, the only other UFA tested that conferred a nominal degree of ethanol tolerance is cis-vaccenic acid (⌬ 11 Z-C 18:1 ), whereas neither ⌬ 11 Z-C 16:1 nor palmitoleic acid (⌬ 9 Z-C 16:1 ) conferred any ethanol tolerance. We also showed that the most ethanol-tolerant transformant, which expresses the insect desaturase TniNPVE, produces twice as much oleic acid as palmitoleic acid in the absence of ethanol and undergoes a fourfold increase in the ratio of oleic acid to palmitoleic acid in response to exposure to 5% ethanol. These findings are consistent with the hypothesis that ethanol tolerance in yeast results from incorporation of oleic acid into lipid membranes, effecting a compensatory decrease in membrane fluidity that counteracts the fluidizing effects of ethanol.

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Reconstitution of Hepatic Microsomal Stearoyl-Coenzyme A Desaturase System from Solubilized Components*

Cited by 170 publications

References 0 publications

Assessment of coastal pollution by combined determination of chemical and biochemical markers in Mullus barbatus

Assessment of coastal pollution by combined determination of chemical and biochemical markers in Mullus barbatus

Distinct regulation of stearoyl-CoA desaturase 1 gene expression by cis and trans C18:1 fatty acids in human aortic smooth muscle cells

Ethanol Tolerance in the YeastSaccharomyces cerevisiaeIs Dependent on Cellular Oleic Acid Content

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